Zed Head

I used a broken shovel handle and the seat back. It worked surprisingly well, several times. Make sure the vinyl of the seat can handle the handle end though. Don't want new cracks. Crack bleed screw, press brake pedal down with shovel handle, prop against seat back, close bleed screw, release handle. If the clear tube is set up with an upward curve you can see if any air bubbles came out.

I did not know this. I've seen the Z series in the wrecking yards but never noticed that it was tilted the other way. Wonder why they did that. They have two spark plugs per cylinder also and 8 terminals in the distributor cap. It's an odd engine. Apparently they were called NAP-Z here in the states. https://en.wikipedia.org/wiki/Nissan_Z_engine Note: All USDM gasoline Z20, Z22 and Z24 engines were known as NAPS-Z (NAPZ or NAPS-Z Nissan Anti-Pollution System), NAPZ motors had dual spark-plugs (two per cylinder) except the pre-82 versions and latest versions of the Z24i as fitted to the Pathfinder. All NAPZ engines sold in California reportedly had dual plug heads regardless of the year.

I can't think of a single time where I've read about the need for a higher capacity mechanical pump. Never read of any engine running lean because the mechanical pump couldn't keep the float bowls full. It might be a thing but I've never heard of it happening. A mechanical pump delivers a certain volume of fuel with each pump, and the pumps are tied to each engine revolution which also pumps about the same amount of air. Doesn't really help your quest but I don't think that you can make a direct comparison between the two types of pump. One's capacity increases automatically, the other's is constant.

Doesn't it depend on engine RPM? It's eccentric actuated.

You might not have the time but this guy went way deep in to all of the 5 speed details. https://forums.hybridz.org/topic/110792-high-rpm-shifting-dynamics/#comments

Just noticed the part about the bellhousing. I think that's an L series versus V6 issue. 2nd edit - Rockauto does not show a V6 for a Nissan pickup in those years. So they should both be L series bolt pattern. Edit - picked the wrong year before. Corrected. https://www.rockauto.com/en/catalog/nissan,1983,720+pickup https://www.rockauto.com/en/catalog/nissan,1985 Carry on...

Brake light on? Bleed screw on top?

This "long-tail" sounds great. I've not read of any of these 71B's being longer than a ZX 5 speed but I have read of the shorter truck 5 speeds. If you're unsure about length ask the guy to measure it end to end. You should have enough remains around to compare and be sure. I'll bet it's ZX length. Get some Redline MT90 in it and it will probably make you cry after all you've been through.

Nothing wrong with using it. Just be aware of the new risks. Contaminated electrodes and over-torquing. https://www.antiseize.com/PDFs/torque_specifications.pdf

Somebody is selling a pretty good replica. Might be the simplest route. https://www.rockauto.com/en/catalog/nissan,1973,240z,2.4l+l6,1209170,electrical,voltage+regulator,4884 https://www.rockauto.com/en/moreinfo.php?pk=45627&cc=1209170&pt=4884&jsn=378&jsn=378

I think the key is where the exit hole is inside the cylinder. Sometimes they drill at an angle and the position of the external threaded hole is misleading. Anybody have a spare cylinder they can take apart and examine?

I wonder what the story is behind ThreePedalCollective? The buyer back in 2019. Has not commented since last October. Bought quite a few cars in just a couple of years on BAT. Why sell the Z that was recently bought, with no reserve price set? Maybe ThreePedal decided this one was a poor investment and wanted to cash out. There would probably be some nervous Z owners out there if it had sold at less than $68,000. Investments are "supposed" to continuously increase in value. https://bringatrailer.com/member/threepedalcollective/

I don't think that one person makes a market. He went up $20,750 in one step and nobody even tried to add $100 to his perceived value. He picked up a number that felt "right" to him. But, if he has the money that's his prerogative.

The smoke could have just been vapors coming back from an open valve. You'll want to measure cylinder pressure before assuming you have a bad head gasket. The thrown rocker arm could happen because of a sticking valve, maybe a tight guide or valve seal. I'd just keep doing the small things to get it to run correctly and let the parts wear in and see where you end up. No need for panic.

What do you think about the replacement guts? Here's a better option. A Ford product with pins. And A, S, and L labels on them. https://www.rockauto.com/en/moreinfo.php?pk=45730&cc=1414673&pt=4884&jsn=587

The thought has crossed my mind about installing an electronic regulator inside the mechanical reg's box. Kind of like using a GM HEI module inside the box of an older ignition module. But if you want to keep what you have why not just drill the rivets or whatever is holding the parts and then replicate them after replating? Here's an example of an internal regular that might work inside the metal box. You'd need to find the pin diagram but I think that it should work. I picked a Nissan one but they're all the same general principle. https://www.rockauto.com/en/moreinfo.php?pk=45661&cc=1209350&pt=4884&jsn=384

There's something fishy about that sale. Somebody artificially supporting the "value" I think. It sold for the same number back in 2019. Looks like a collector maybe inflating asset values. Might even be illegal, I don't know. Just talking, no offense intended. There's no logical reason to bump a bid by $20,750 when a typical bump is in the single digit thousands. https://bringatrailer.com/listing/1970-datsun-240z-36/

This might be tempting but probably better done with a 280Z. https://forums.hybridz.org/topic/46198-a-mopared-datsun/?do=findComment&comment=392601

There's a rubber boot around the rod that passes in to the booster. And there's a valve in the booster that releases the vacuum when you move the pedal. Not sure that the noise is a sign of a bad booster. Might just be air moving through the valve and/or other orifices. There are simple ways to check booster function beyond listening for engine speed changes, although the engine idle speed change is a good one. If your idle speed doesn't change when you use the brakes your booster is probably fine. Here's one of many booster check procedures out there. https://www.knowyourparts.com/technical-resources/brakes-and-brake-components/vacuum-booster-diagnostics/

The last bid was a $20,750 raise. $47,250 to $68,000. The guy looks like he's establishing a collector price, not trying to get a deal. Wonder if he needs to hit a number for a tax break. Kind of an odd bid.

A different kind of Datsun. https://bringatrailer.com/listing/1971-datsun-510-station-wagon-6/

This one is up today. Sitting at $68,000 with three plus hours left.

Avocado green 72. Lots of originalness. https://bringatrailer.com/listing/1972-datsun-240z-191/

Two more might be blown FPR diaphragm and bad/disconnected/high resistance coolant temperature sensor. This book is good. You really really really need a multimeter to work on EFI. Hope you have one. There's an Electrical Test section.